Euronews Next visited IBM’s research lab in Zurich to find out more about the field that promised to usher in new solutions to the world’s problems.

Depending on who you ask, some say quantum computers could either break the Internet, rendering virtually all data security protocols obsolete, or allow us to calculate our way out of the climate crisis.

These hyper-powerful devices, an emerging technology that exploits the properties of quantum mechanics, are much buzzed about.

Last November, IBM unveiled its latest quantum computer, the Osprey, a new 433-qubit processor that is three times more powerful than its predecessor, which was only built in 2021.

But what is all the hype about?

Quantum is a field of science that studies the physical properties of nature at the scale of atoms and subatomic particles.

Proponents of quantum technology say these machines could usher in rapid advances in fields such as drug discovery and materials science — a prospect that dwarfs the tantalizing prospect of creating, for example, lighter, more efficient electric vehicle batteries or materials that can facilitate efficient CO2 capture.

With the climate crisis looming and technology with a hope of solving complex issues like these will definitely attract a lot of interest.

It’s no wonder that some of the biggest technology companies in the world – Google, Microsoft, Amazon and, of course, IBM to name a few – are investing heavily in it and are looking to stake their place in a quantum future.

## How do quantum computers work?

Given that these utopian-sounding machines are attracting such frenzied interest, perhaps it would be useful to understand how they work and what differentiates them from classic computing.

Take all the devices we have today – from the smartphones in our pockets to our most powerful supercomputers. These work and have always worked on the same principle of binary code.

Basically, the chips in our computers use tiny transistors that act as on/off switches to provide two possible values, 0 or 1, also called bits, short for binary numbers.

These bits can be configured into larger, more complex units, essentially long strings of zeros and ones encoded with data commands that tell the computer what to do: display a video; view a Facebook post; play an mp3; allows you to write an email and so on.

But a quantum computer?

These machines work in a completely different way. Instead of bits in a classical computer, the basic unit of information in quantum computing is what is called a quantum bit or qubit. These are usually subatomic particles such as photons or electrons.

The key to a quantum machine’s advanced computing power lies in its ability to manipulate these qubits.

“A qubit is a two-level quantum system that allows you to store quantum information,” Ivano Tavernelli, global leader of advanced algorithms for quantum simulations at the IBM Research Lab in Zurich, explained to Euronews Next.

“Instead of just having the two levels zero and one that you would have in a classical calculation here, we can build a superposition of these two states,” he added.

## Superposition

Superposition in qubits means that unlike a binary system with its two possible values, 0 or 1, a qubit in superposition can be 0 or 1 or 0 and 1 at the same time.

And if you can’t wrap your head around that, the analogy often given is a penny.

When standing still, a penny has two faces, heads or tails. But if you turn it around? Or spin it? In a way it is both head and tail at the same time until it lands and you can measure it.

And for computing, this ability to be in multiple states simultaneously means you have an exponentially larger amount of states to encode data, making quantum computers exponentially more powerful than traditional binary code computers.

## Quantum entanglement

Another property crucial to how quantum computing works is entanglement. It is a somewhat mysterious feature of quantum mechanics that even puzzled Einstein in his day who declared it to be “spooky action at a distance”.

When two qubits are generated in an entangled state, there is a directly measurable correlation between what happens to one qubit in an entangled pair and what happens to the other, no matter how far apart they are. This phenomenon has no counterpart in the classical world.

“This property of entanglement is very important because it provides a much, much stronger connection between the different units and qubits. So the processing power of this system is stronger and better than the classical computer,” Alessandro Curioni, director of the IBM Research Lab in Zurich, explained to Euronews Next.

In fact, this year the Nobel Prize in Physics was awarded to three scientists, Alain Aspect, John Clauser and Anton Zeilinger, for their experiments on entanglement and advancement of the field of quantum information.

## Why do we need quantum computers?

So in an admittedly simplified nutshell, these are the building blocks of how quantum computers work.

But then again, why do we necessarily need such hyper-powerful machines when we already have supercomputers?

“(The quantum computer) will make, much easier, the simulation of the physical world,” he said.

“A quantum computer will be able to simulate the quantum world better, so simulating atoms and molecules”.

As Curioni explains, this will allow quantum computers to aid in the design and discovery of new materials with tailored properties.

“If I can design a better material for energy storage, I can solve the problem of mobility. If I can design a better material as a fertilizer, I can solve the problem of hunger and food production. If I I can design a new material that allows (us) to CO2 capture, I can solve the problem of climate change,” he said.

## Unwanted side effects?

But there may also be some unwanted side effects that need to be considered as we enter the quantum age.

A primary concern is that the quantum computers of the future could have such powerful computing power that they could break the encryption protocols that are fundamental to the security of the Internet we have today.

“When people communicate over the Internet, anyone can listen to the conversation. So they have to be encrypted first. And the way encryption works between two people who haven’t met is that they have to rely on some algorithms called RSA or Elliptic Curve , Diffie–Hellman , to exchange a secret key,” explained Vadim Lyubashevsky, a cryptographer at the IBM Research Lab in Zurich.

“Exchanging the secret key is the hard part, and they require some mathematical assumptions that break down with quantum computers”.

To protect against this, Lyubashevsky says that organizations and government actors should already update their cryptography to quantum-safe algorithms ie. ones that cannot be broken by quantum computers.

Many of these algorithms have already been built and others are under development.

“Even if we don’t have a quantum computer, we can write algorithms and we know what it’s going to do once it’s there, how it’s going to run those algorithms,” he said.

“We have concrete expectations about what a certain quantum computer will do and how it will break certain encryption schemes or certain other cryptographic systems. So we can definitely prepare for things like that,” Lyubashevsky added.

“And it makes sense. It makes sense to prepare for things like that because we know exactly what they’re going to do”.

But then there is the issue of data that already exists and has not been encrypted with quantum-safe algorithms.

“There is a very big danger that government organizations right now are already storing a lot of internet traffic in the hope that once they build a quantum computer they will be able to decipher it,” he said.

“So, even though things are still secure now, maybe something is transmitted now that will still be interesting in 10, 15 years. And that’s when the government, whoever builds a quantum computer, will be able to decrypt it and maybe use that information that he should not use”.

Even so, weighed against the potential benefits of quantum computing, Lyubashevsky says these risks should not stop the development of these machines.

“Breaking cryptography is not the point of quantum computers, it’s just a side effect,” he said.

“It will hopefully have much more useful tools like increasing the speed at which you can detect chemical reactions and use that for medicine and things like that. So this is the point of a quantum computer,” he added.

“And sure, that has the negative side effect that it will break cryptography. But that’s not a reason not to build a quantum computer, because we can fix it and we have fixed it. So it’s an easy problem to solve there.” .

**For more on this story, watch the explainer video in the media player above.**

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